Dyrosauridae

Jouve, Stéphane, Muizon, Christian De, Cespedes-Paz, Ricardo, Sossa-Soruco, Víctor & Knoll, Stephane, 2021, The longirostrine crocodyliforms from Bolivia and their evolution through the Cretaceous-Palaeogene boundary, Zoological Journal of the Linnean Society 192, pp. 475-509 : 502

Dyrosauridae

The early Palaeocene Bolivian dyrosaurid fauna seems to have been well diversified, with at least three species ( Table 2). Three of them are found in the Tiupampa ‘Quarry’, one of them in Torotoro and at least two in Blanco Rancho. All three species are new to science. This dyrosaurid fauna is formed by a large, tube-snouted form with slender teeth, a smaller, slender, short-snouted form with slender teeth, and a species with a short snout and large and probably robust teeth. The morphology of these dyrosaurids is distributed into three different morphological guilds characterized by their snout length/tooth size associations. This separation probably limited the diet competition between the three contemporaneous species, a distribution previously observed in dyrosaurids from the Oulad Abdoun Basin of Morocco in several stratigraphic levels (Jouve, 2004; Bardet et al., 2010), the Palaeocene of the Cerrejon Formation in Colombia ( Hastings, 2012) and the middle Eocene of Germany ( Hastings & Hellmund, 2017). Such niche partitioning has also been suggested for Mesozoic marine thalattosuchians ( de Andrade & Young, 2008), freshwater crocodyliforms ( Moreno-Bernal et al., 2006) and marine Mesozoic squamates ( Bardet, 2012; Bardet et al., 2015).